<header for='back' class="big_header">
    <a href="javascript:;" class='lhb_header_logo'>
        <img src="http://www.ak48.xyz:9090/images/header_logo.png" alt="">
    </a>
    <a href="javascript:;" class='lhb_header_app'>
        <img src="http://www.ak48.xyz:9090/images/header_app.png" alt="">
    </a>
</header>
<div class="lhb_search">
    <form action="">
        <input type="search" placeholder="请输入你想比价的商品">
        <input type="submit" value='搜索'>
    </form>
</div>